A great many different designs for fuel injectors are well known and widely used. Over the years, various concerns have driven technological innovation in fuel injectors and other components of fuel systems. Notable among these has been the desire to inject fuel at increasingly high pressures. High fuel pressures have been shown to be associated with relatively greater fuel atomization and the reduction of certain emissions from an associated engine. Recent attempts have been made to inject fuel from a fuel injector into an associated engine cylinder at pressures of 200 MPa or greater. While showing much promise for further improving and optimizing the operation of engine systems, in particular compression ignition diesel engine systems, such extremely high pressures have presented a number of challenges in conventional systems. One known type of fuel injector includes a body guide having a guide bore for a nozzle check, a nozzle chamber and a nozzle casing within which the body guide is received. In research situations, it has been discovered that extremely high fuel pressures within a fuel injector of this type can cause certain components to fail. In particular, in some instances the nozzle cavity can actually crack.
Certain relatively large fuel injectors tend to be more capable of handling extremely high internal fuel pressures. Many engine and fuel system components, however, are purpose built for fuel injectors of a certain size. Simply making fuel injectors larger to handle greater pressures is therefore not desirable in many instances.